Resilient mechanical wheel



June 25, 1946. w o BEYER ETAL 2,402,594

RESILIENT MECHANICAL WHEEL Filed Nov. 15, 194::

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as, cammmfiafa aw Patented June 25, 1946 UNITED STATES PATENT OFFICE Walter-0. Beyer and Thomas R. Tarn, Pittsburgh, Pa.

Application November 15, 1943;531:1131 N0. 510,388

The present invention pertains to a novel resilient wheel of the type wherei'n an annular helical spring is disposed between the wheel body or center and the outer rim. The general object of the invention is "to enable demountability and interchangeability of like parts. For example, the surface "wearing material may be replaced without requiring replacement of the spring. "The wearing material may be flexible but not necessarily resilient in a high degree.

Another object of the invention "is to provide a spring construction wherein any angular displacement of the rigid external rim assembly with respect to the wheel center'will instantaneously produce proportional displacements of coil turn portions uniformly distributed. This object is accomplished by fixing and articulating each coil turn at equal intervals about the wheel. The specific structure ior this purpose is in the nature of aniannular cage contained in the spring and in which each winding is secured.

illustrative embodiment of the invention is fully disclosed in the following description and in the accompanying drawing in which:

Figure 1 is aside elevation of a wheel according to the invention;

Figure 2 is a sectional line 2-2 of Figure 1, and

Figure 3 is a detail section on the line 3--3 of Figure 2.

In Figure 2 is shown a Wheel body or center I carrying a peripheral rim member 2 having substantially a U section opening outward. An annular coil spring 3 is seated in this rim. The manner of assembly will subsequently be described. The diameter of each coil is relatively large with respect to the diameter of wire used to make up the spring.

The spring is clamped to the internal rim 2 by means of an annular band 4 preferably formed with outwardly diverging sides 5 which are shaped to engage the coils. The spring-engaging surface of each side 5 is formed with channels 6 in which the coils are individually received. The channeled parts of the band are preferably fitted in pockets or in the rim 2. The sides 5 are bolted to the rim 2 as indicated by the numeral 8, preferably at 30 degree intervals, whereby the band 4 clamps the spring to the rim 2. The band is further formed with a central peripheral rib 9 formed with notches I individually receiving the coils and serving as space dividers.

A similar band H i fitted within the spring annulus, outward of the band 4 and also engages the coils preferably through the medium of diverging side portions l2. The edges of the latter 2 are formed with milled slots 13 individually receiving the coils and serving as space dividers in "the same manner as the channels :6 and notches it. The member :II is also formed with an outwardly directed central peripheral rib M having notches 1'5 which individually receive the coils.

The outer rim assembly is supported by the member H and includes a pai-r of annular collars It bolted respectively at [3 to the side portions 2 at regular intervals of approximately 30 degrees. It will be apparent that the bolts it, as well as the bolts '8, pass between the coils of the spring. The rim assembly is completed by an external rim member l9, preferably of channel formation, secured across and to the member 16 by suitable means such as rivets .20. In the channel member is inserted suitable tread material '21 which is preferably flexible but not necessarily resilient.

in order to assemble the complete wheel, the wheel center or body I may be laid within the external rim assembly but offset axially so that the edge of one collar 15 contacts the smaller diameter of the wheel body. Thus, the clearance space directly opposite such point of contact is approximately the difference between the internal diameter of the external rim assembly and the inner diameter of the wheel body. It follows that when the helical coil member is compressed to form an arc of a circle, it can be laid within the clearance space. The external rim assembly and the wheel body are then adjusted concentrically in order to permit the compressed helical coil member to extend from an arc of a circle to a full circle within the annular space between the external rim member 19 and the wheel body 'I,

. by virtue of the sides of the inner rim 2 and the inwardly extending collars 16 of the external rim assembly. Bands 4 and l I, which have been pre viously located within the spring, are then drawn into position for fastening to the parts 2 and it. By means of the bands 4 and II, each coil turn is fixed and articulated to the external rim assembly and to the wheel body I at each point of contact with the respective collar portions IS. The ends of the wire constituting the spring are finally joined so that the helical coil becomes endless.

In the use of the wheel mounted upon the axle of a vehicle, the gravity load upon the axle and wheel body I is supported from the upper half of the rigid external rim assembly by the coil resiliently in tension, bending and torsion. In addition thereto, the gravity load upon the wheel body I and axle is provided by the lower half of the rigid external rim assembly through the coils resiliently in compression, bending and torsion. In other words, approximately one-half of the axle load is carried in the same manner as for ordinary wheels, except that the helical annulus introduces resilience of support for gravity load for every phase of gravity load supporting action.

When torque is applied to the axle and the wheel center I, either by motiv power or wheel brakes, thereby setting up forces tangential to the wheel, such tangential load is automatically, simultaneously and uniformly distributed among the coil turns of the helical annulus, introducing uniform torsional and bending stress in the rod or wire making up the coil. Since each coil turn is fixed and articulated at equal intervals about the wheel, any angular displacement of the rigid external rim assembly with respect to the wheel body I- must instantaneously produce proportional displacements of coil turn portions which must be uniformly equal by reason of the fixed end symmetrical positioning of said coil turns.

Each coil turn is positioned and retained, structurally, by a force couple applied to the radially outward portion of each coil turn and also by a force couple applied to the radially inward portion of each coil turn. The rotational tendencies of each pair of force couples are opposed, with the effect that each coil turn is located and stabilized by the fixed attachments which give rise to the force couple.

The annular helical coil as a body is positioned concentrically and laterally by the outwardly convex nature of the wheel center rim and the inwardly convex nature of the outer rim assembly at the collars 16.

While a specific embodiment of the invention has been illustrated and described, it is intended that various alterations in the details of construction may be made without departing from the invention as indicated by th scope of the appended claims.

What we claim is:

1. In a wheel, a central body, an annular helical spring surrounding said body, a rim surrounding said spring, and a pair of clamping bands within said spring and secured respectively to said body and rim, said bands having recesses individually receiving the coils of said spring, and a peripheral rim extending from each band and having notches individually receiving said coils.

2. In a wheel, a central body havin an outwardly concave rim, an annular helical spring surrounding said body and seated in said rim, and external rim surrounding said spring and having an inwardly concave portion fitted on said spring, and a pair of clamping bands within said spring and secured respectively to said rims, said bands having recesses individually receiving the coils of said spring, and a peripheral rim extending from each band and having notches individually receiving said coils.

3. In a wheel, a central body, an annular helical spring surrounding said body, a rim surrounding said spring, and a pair of clamping bands individually securing equidistantly each of the coils of said spring, and a peripheral rim extending from each band and having notches individually receiving said coils. n

4, In a wheel, a central inner member, an an:- nular helical spring surrounding said inner member, an outer member surrounding said spring, means for clamping each coil turn of said spring against one of said members only at helically spaced points so as to leave free and substantially unrestrained the portion of each coil turn spanning the latter member between said points and means for connecting said spring tothe other of said members.

5. In a wheel, a central inner member, an annular helical spring surrounding said inner member, an outer member surrounding said spring, means for clamping each coil turn of said spring against one of said members only at helically spaced points so as to leave free and substantially unrestrained the portion of each coil turn spanning the latter member between said points, means between said points on said one of said members for spacing each coil turn of said spring, and means for connecting said spring-to the other of said members.

WALTER 0. BEYER. THOMAS R. TARN. 

